zgomotron

Zgomotron (from the Romanian word zgomot = noise) was another interesting project I developed for Modulab during the late-night work of an autumn evening in 2016. Modulab was organizing an electronics workshop for children aged 12 or younger at their workspace and I was in charge of designing and manufacture the electronics for this activity. The final product that the participants had to assemble, Zgomotron, was a noise-producing circuit which changed its frequency with the light level of the room.

We’ve chosen for this workshop a simple application with a 555 IC circuit oscillating at a low frequency in the audio specter with a speaker connected at its output. The oscillating frequency was determined by the reaction of R1 and R2 with capacitor C1 (see Figure 2). The whole project was interactive since R1 was a photoresistor increasing the sound frequency when the illuminance level in the room was increasing.

I designed the layout for one circuit and then panelized it in a 3 by 3 matrix. Using Press’n’Peel technology I transferred the design onto a single-sided FR4 board and etched it with ferric chloride. You can observe in Figure 3 the boards before the drilling and in Figure 4 after the drilling performed using a Dremel multi-purpose tool. Also by using the Dremel tool I cut the board from the panel as displayed in Figure 5.

One last operation to be done before packing up the boards with the necessary components as seen in Figure 7 was to solder the 555 IC. We decided to do that in advance since no notch mark was present on the boards and the young participant could easily misplace this component, leading to a major malfunction. Displayed in Figure 6 are the boards with the IC soldered and one completely assembled to serve as a model.